1. Technical Field of the Invention
The present invention relates to an optical disc apparatus in which an optical pickup and a circuit board with a signal-processing circuit are interconnected via a flexible printed-wiring circuit board. The invention relates more particularly to a technique for protecting an electrical line of the wiring board.
2. Description of the Related Art
Optical disc apparatuses having an optical pickup adapted to enable the emission of tri-channel laser light inclusive of blue laser light are coming to be used in recent years. Such an optical pickup is dimensionally increasing, and at the same time, a flexible printed-wiring board is also growing in surface area with a quantitative increase in wiring. Since using connectors to connect such a flexible printed-wiring board to the optical pickup is liable to render the reliability of the connection unable to be ensured, the flexible printed-wiring board is connected to the optical pickup directly, not via connectors. Accordingly, if the causes of defects such as damage occur in the flexible printed-wiring board, the optical pickup also requires replacement, which poses problems associated with costs, in particular. If the flexible printed-wiring board with a large surface area is of a fold-back structure, the fold-back portion increases in curvature radius, thus causing further inconvenience such as swelling the wiring board at the optical pickup side and bringing the swelling section into contact with the moving optical pickup. Technology that allows the flexible printed-wiring board to be fixed to prevent or suppress such swelling and protect the wiring board is being called for to improve the above problems.
Conventional techniques related to the present invention and intended to keep the fold-back portion of a flexible printed-wiring board from swelling include the technique described in, for example, Japanese Utility Model Registration No. Sho 64-39691. This Publication describes the technique for fixing a band-shaped flexible printed-wiring strip (flexible printed-wiring board) by, at the fold-back portion of the wiring board that is formed at the end of a fixing plate member, holding down the fixing plate member and both sides of the wiring strip flexibly, in the direction of the plate thickness, and in sandwiched form, with a perpendicularly cornered rectangular hook-shaped clamping member.
In such conventional technique as outlined above, the perpendicularly cornered rectangular hook-shaped clamping member is abutted directly on the surface of the flexible printed-wiring strip and the resilience of the clamping member presses the surface of the flexible printed-wiring strip to fix the wiring strip. This construction of the flexible printed-wiring strip, however, is likely to cause several unfavorable events. (1) A first unfavorable event is that since stress concentration on the flexible printed-wiring strip easily occurs at the edge of the clamping member, the wiring section of the flexible printed-wiring strip is prone to damage. (2) A second unfavorable event is that since the clamping member presses the surface of the flexible printed-wiring strip, the surface easily becomes damaged, and that this also happens when the clamping member is mounted. (3) A third unfavorable event is that the use of the perpendicularly cornered rectangular hook-shaped clamping member dimensionally increases an associated planar section.
With the above situation of the conventional technique taken into account, the present invention was made so that the internal flexible printed-wiring board of an optical disc apparatus that interconnects an optical pickup and a circuit board having a signal-processing circuit can be fixed without forming a swelling section, even at a fold-back portion, by using a method that enables easy mounting in a simplified configuration and does not damage the surface or wiring section of the flexible printed-wiring board.
An objective of the present invention is to provide an optical disc apparatus that solves related problems and is improved in reliability.